Conventional reproducing machines are mainly classed into two types, one being of a type that reproduces a recorded sound by rotating a record or sheet, and the other being of a type that reproduces a recorded sound by rotating a reproducer stylus or the like with a record or sheet stationary. These machines generally use a record or sheet with a spiral groove which is played back for a relatively long time. Therefore, the machines are not suitable when a playback of a relatively short time is required.
Nowadays, demands are increasing for records or sheets of a short time of reproduction which contain information such as words or phrases for the purpose of learning a foreign language and which are used as word books.
The present invention provides a useful means of reproducing such information recorded on a sheet which has a width of recorded area between, e.g. an outer diameter of 40 mm and an inner diameter of 15 mm, and therefore of a reproducing time of 30 seconds.
A sheet of small size and therefore of a short time of reproduction is provided according to the present invention, and is used for high speed rotation or 78 r.p.m. The sheet has no hole centrally thereof for placing it correctly on a turntable but is readily positioned and removed. A pickup arm with a stylus is automatically set at the starting point of the sheet. More particularly, a rod member is provided, which is adapted to move up and down and acts as a switch for detecting if a sheet is loaded or not. The rod member is normally in a projecting state, and in this state the sheet is placed on the turntable. The sheet is first inclined relative to the turntable as supported by the rod member and is therefore easy to catch or grasp by the operation. When a pivotted lid of the apparatus is lowered to a closed position, it presses down the sheet which also depresses the rod member, placing the sheet horizontally on the turntable and actuating a switch for a motor to drive the turntable.
A sheet provided according to the invention has no hole centrally thereof for positioning the sheet on the turntable. This makes it possible to use all the surface area of the sheet for visual information. As the sheet has no such hole, provision is made so that the corners or edges of the sheet are held by the peripheral portion of the turntable.
A conventional reproducing machine includes a mechanism of complicated construction which permits an automatic return of a pickup arm to its original position.
According to the present invention, however, a pivotted lid is provided with a frame member for supporting a head portion of a pickup arm, and a guide supporting frame which is located in a position where the head portion of the pickup arm receives a component force which moves the arm away from the center of the sheet when the lid is moved up. In this manner, the pickup arm is returned to its original position by its own weight when the lid is moved up.
As understood from the aforegoing, the present invention provides a very simplified means of returning the pickup arm to its original position.